Brake boosters of said type are nowadays employed as large-scale production products for the amplification of the actuation force which is applied by the driver of a vehicle to the brake pedal during a braking operation. An input member of the brake booster, which is connected to the brake pedal, transmits the actuation force applied by the driver to the brake booster which amplifies said force and supplies it via an output member to a downstream master cylinder which is connected to the brake booster.
The brake booster is to respond as directly as possible to a variation of the actuation force exerted by the driver and correspondingly increase or decrease, respectively, the force assistance. This means that the air volume which is required for venting the working chamber of the brake booster must be supplied as rapidly as possible. Due to the rapidly incoming air undesired noise may occur, and it is known to reduce this noise to an extent which no longer constitutes a disturbance by means of sound-absorbing material, for example in the form of a sound-absorbing liner (see also DE-B-29 18 734).